Question

I’m new to regular expressions.

The following code works as expected, printing first “true” and then “false”, the backslash in front of the period escaping it:

var pattern = new RegExp(/\./);
document.write(pattern.test("."));
document.write(pattern.test("a"));

But why does the following print “false”:

var pattern = new RegExp(/\b\./);
document.write(pattern.test("."));

The period is, after all, at the beginning of the string.

Answer 1

You want to try using ^ –

/^\./

If you have

/\b\./

it matches the .‘s in Hello. How are you.